Nickel-cobalt heat-resisting alloy



Patented May 30, 1950 UNITED STATES PATENT OFFICE No Drawing. Application November 20, 1946,

Serial No. 711,197.

3 Claims. 1

This invention relates generally to alloys having a high degree of resistance to the combined and continued action of intense heat and stress, and particularly relates to alloys which are used in the construction of gas turbine parts.

The gas turbine type of engine consists mainly of a shaft having mounted thereon an air compressor and a hot gas turbine, the rotation being imparted to the engine by the action of the hot gases upon the gas turbine during expansion. The heat of the flaming gases, acting upon the blades and buckets, causes the corrosion and rupture of the metal used in their manufacture in a comparatively short time. It may, therefore, be safely stated that the development of the gas turbine depends upon the development of proper alloys to withstand the intense heat involved in its operation.

It is therefore the object of this invention to provide an alloy which will withstand intense heat and stress for a long period of time.

A more specific object of this invention is to provide an alloy which will withstand high mechanical stress at a temperature of 1500 F. or more for a comparatively long period of operation.

With these objects in view the present invention consists in an alloy comprising cobalt, chromium, nickel, copper, molybdenum, boron and iron.

These metals may be melted together in the usual manner to form the improved alloy.

In the course of the research done in connection with the improved alloy, a large number of combinations in various proportions were made, outstanding among these and exemplary of them are the following two combinations:

Preliminary tests on the alloy within the range of the above compositions show the following:

In Canada December 19,

Rupture Elongation Stress Reduction of p. s. i 5 per 95" in area, per cent 1 1 Graph of Time-Rupture line indicates that it would continue to 2600 hours.

The above tests have been carried out under a temperature of 1500 F.

Other alloys, having the same properties as those described above, but having a chromium content varying from 15% to 25 have also shown good results; these alloys also containing from 40 to 50% of cobalt, 10 to 20% of nickel, 5 to 6% of copper, 4 to 5% of molybdenum, 9.75 of iron, and 0.25% of boron.

The foregoing description is given by way of example only and without intention to limit the invention to the proportions stated.

What I claim is:

1. A castable alloy adapted for use in the construction of gas engine parts and characterized by high heat and stress resistance consisting of the following metals in the proportions by weight of cobalt 40 to 50%, nickel 10 to 20%, chromium 15 to 25%, copper 5 to 6 molybdenum 4 to 5%, iron 9.75% and boron 0.25%.

2. A castable alloy adapted for use in the construction of gas engine parts and characterized by high heat and stress resistance consisting substantially of the following metals in the proportions by weight of cobalt 50%, chromium 20%, nickel 10%, iron 9.75%, copper 5%, molybdenum 5% and boron 0.25%.

3. A castable alloy adapted for use in the construction of gas engine parts and characterized by high heat and stress resistance consisting substantially of the following metals in the proportions by weight of cobalt 40%, chromium 20%, nickel 20%, iron 9.75%, copper 6%, molybdenum 4% and boron 0.25%.

PETER FORBES BLACKWOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,115,238 Parr Oct. 27, 1914 1,203,555 Brix' Oct. 31. 1916 2,030,343 Wissler Feb. 11, 1936 2,156,757 Grossman May 2, 1936 2,246,078 Rohn et a1 June 17, 1941 2,309,136 Neiman Jan. 26, 1943 Pfeil May 14, 1946 

1. A CASTABLE ALLOY ADAPTED FOR USE IN THE CONSTRUCTION OF GAS ENGINE PARTS AND CHARACTERIZED BY HIGH HEAT AND STRESS RESISTANCE CONSISTING OF THE FOLLOWING METALS IN THE PROPORTIONS BY WEIGHT OF COBALT 40 TO 50%, NICKEL 10 TO 20%, CHROMIUM 15 TO 25%, COPPER 5 TO 6%, MOLEBDENUM 4 TO 5%, IRON 9.75% AND BORON 0.25%. 